US2399191A - Production of slivers of artificial fibers - Google Patents

Description

April 1946- I w. e. ABBOTT, JR 1 PRODUCTION OF SLIVERS OF ARTIFICIAL FIBERS Filed Oct. 18, 1945 hing either directly or after drawing.

' continuous Patented Apr. 30, 1946 PRODUCTION OF SLIVERS F ARTmCIAL Y FIBERS William G. Abbott, Jr... Milford, N. n. Application October 18, 1943, Serial No. "506.56% Claims. (on. 18-54) This invention relates to the production of slivers consisting of artificial fibers of staple length staggered and overlapped in the sliver, such, for example, as would be suitable for spin- The practical method of forming artificial fibrous material by extrusion is to extrude the material in liquid or plastic form through a spinneret having a considerable number of minute orifices and harden the material by one of several operations such as causing coagulation of the material is a bath, or permitting a solvent for the material to vaporize, or permitting a material of a thermoplastic nature to cool. I

The sliver so produced can be cut into staple lengths and worked on to distribute the pieces of fibers lengthwise in proper overlapping relation. It has been proposed to avoid the cutting operation by intermittently interrupting the flow of liquid material to the orifices of a spinneret so as to produce initially a discontinuous sliver consisting of sections each of staple length. But with such a proposed procedure the sliver after its formation would still need to be mechanically treated to distribute the fibers thereof in proper overlapping relation lengthwise of the sliver.

The present invention aims to avoid the nemessity for distributing the staple lengths of fibers after the formation of the sliver, and aims to form the sliver, in the first instance, with its individual fibers of staple length and properly A suitable coagulating solution :2 is maintained in a tank it into which the spinneret Ii disfiber-forming substance of rial.

As applied to the extrusion of a solution of viscose, the coagulating bath may, for example, consistof:

. the extruded matein aqueous solution.

The spinneret H may be supplied with material by suitable means such as a pump it receiving its supply from a tank it. The tank i5 is preferably provided with agitating mechanism, such, for instance, as a motor-driven propeller l6, adapted to maintain the material in a thoroughly mixed condition, as more fully explained below.

overlapped and distributed lengthwise in the sliver.

Other objects and advantages of the invention will be apparent from the specification and its drawing, wherein the invention is described and illustrated by way of example.

In the drawing Fig. 1 is a schematic view of a preferred form of apparatus for practicing the invention;

Fig. 2 is a vertical sectional view, enlarged but not to scale, through a spinneret and coagulating bath, diagrammatically showing the fibers being formed from a composite in which the filament-forming material constitutes the dispersed phase; and

According to the invention, the material of which the filaments are to be formed, for example viscose, is maintained in the supply tanl: it in a composite which includes another material which retains its separate identity in the tinuous phase of the composite, suitable for use with viscose, there may be employed a light min- Fig. 3 is a view similar to Fig- 2 showing the the filament-forming material constitutes the ase. I Referring the drawing, a spinneret II is provided, and may be of conventional form, containing the desired large number of extrusion orifices of such number and size as will produce the desired sliver.

7 through the extrusion orifices of the spinneret, the particles of viscose solution passing througheral oil or naphtha which will separate from the coagulating bath by rising to the surface, or a liquid such as carbon disulphide that will separate from the coagulating bath by collecting at the bottom of the tank It.

As the material from the supply tank is forced each orifice are separated lengthwise by the other, removable and non-coagulable, ingredient of the composite. Upon entry into the coagulatcharges the extruded material, the coagulating solution being of .such nature as to solidify the approaching and passing through some of the extrusion orifices, and then being acted on as separate filaments 20 by the coagulating solution .12. Fig. 2 also shows the flow of filament-forming particles interrupted at the moment at some oi the orifices by the passage through those orifices of non-coagulable liquid 2| constituting the.

continuous phase of the composite. This figure also indicates diagrammatically how the separate filaments 28 of the silver are overlapped and staggered longitudinally of the sliver. It will be'understood that this figure shows only a few of the many streams of composite which are extruded simultaneously.

Fig. 3 shows in a diagrammatic way the use of a mixture in which the filament-forming coagulable viscose, indicated at 20, constitutes the continuous phase, with the other material it, separable from thefilament-forming material after extrusion, constituting the dispersed phase, and the formation or the separate filaments 2G in a manner similar to Fig. 2.

Whether the filament-forming material constitutes a dispersed phase, as in Fig. 2, or a continuous phase, as in Fig. 3, the filament-forming material and the other material are so'disposed, substantially uniformly throughout the composite, thebodies of each material will be presented to the individual orifices at frequent intervals, the bodies of said other material filling the oriflee cross-section to the temporary exclusion of the filament-forming material.

Because 01 the considerable number of extrusion orifices in the splnneret and the intimate mixture between thefilament-forming material and the other material, the resulting staple length fibers are distributed fairly evenly length- .wise of the silver. The silver so produced consists of a number of parallel laid fibers, of staple but more or less uneven length, overlaid in a more or less uneven pattern, the silver itself being of fairly uniform weight and diameter along its length.

Preferably, in order to insure even action of the coagulating solution on the material and to hold the fibers together loosely while they are being hardened by coagulation and the other material of the composite is being separated from them, they are confined laterally in the coagulating bath by a tube 25, which may be perforated. A suitable amount of twist can be iniparted to the sliver by a relative rotation of the spinneret H and tank i3 in which the sliver is formed. For simplicity, the tank i3 is shown as mounted for rotation with a turntable 21.. Such rotation of the coagulating tank l3 not only serves to impart the desired slight twist to the sliver, but also serves to coil the sliver in a fairly even form at the bottom of the tank.

The invention is also applicable to processes inwhich no twist is imparted to the sliver, and various forms of means may be employed to hold the sliver together during hardening and subsequent washing.

During the coagulating action, the coagulating solution may be replenished or changed bythe addition of further coagulating solution through an entrance pipe 30, and excess solution may be allowed to discharge either continuously or intermittently through an overflow pipe 3! leading from the bottom of the tank. A-periorate diaphragm 32, slightly above the entrance of the overflow pipe 3|, serves to support the coils of formed sliver and prevent these from obstructing the entrance to the overflow pipe. A circular trough 33 surrounding the upper end of the retatable tank i3 is provided to catch the overflow from pipe 8!. a

Although for simplicity of illustration the apparatus is shown as being of the type that requires periodic removal of the silver from tank l3, the invention is similarly applicable to processes in which the silver is delivered from the apparatus continuously.

The form of the resulting sliver can be varied by suitable control of the volume of filamentiorming material supplied to the spinneret, the relative proportions of the filament-forming ma terial and the other material of the composite, the relative sizes of the particles of these materials as they pass through the extrusion orifices, and the number and size of extrusion orifices, so

as to produce slivers of the nature of top slivers.

different chemical and mechanicalstructure are blended together.

For example, the composite may have two dispersed phases. One of such dispersed phases may be, for example, casein suitably prepared and reduced to a viscous syrup by an aqueous solution of sodium hydroxide. A second dispersed phase may consist of zein, which is a corn product proteid which after purification is dissolved in alcohol or carbitol to form a thick syrup. These two dispersed phases are preferably dispersed separately in the continuous phase non-coagulable material which may consist of a light coal tar naphtha or heavier chlorinated product in which these dispersed phases are insoluble, and the whole composite thoroughly mixed. As av coa ulating bath for forming this blended sliver, a solution of formaldehyde and water may be employed, and to such solution there may be added acetic acid, glucose or calcium chloride in order to assist the coagulation and hardening of the filaments.

While the mixture has been described by way of example as utilizing a liquid as the other material, separable from the filament-forming material after extrusion, the mixture may utilize gases or semi-solid material for the same purpose.

To further illustrate the invention, it may be applied to filament-forming material that is hardened after extrusion by vaporization of a volatile solvent rather than by use of a coagulating bath. Thus cellulose acetate dissolved in acetone may constitute the filament-forming material, the acetone may be allowed to vaporize to solidify the cellulose acetate, and the other material of the mixture, which retains its separate identity in the composite, may consist of a waxy hydrocarbon of liquid consistency and be removed from the silver by treatment by a solvent.

The invention may also be applied to thermoplastic filament-forming material that is extruded in a plastic condition. Thus, nylon or Vinyon may constitute the filament-forming material and may solidify by cooling after the extrusion of the mixture, and the other material of the mixture may be removed from the silver by treatother material nee les ment by a solvent. In the extrusion of composites in which the filement i'orming material is in a plastic condition, it is preferred that the other material oi the composite be of a plastic nature, such, for example, as a plastic waxy hydrocarbon. As in the other forms of the invention, the materials of the composite are selected so as to retain their separote identities in the mixture.

l clelm:

1. Method of forming a sliver of artificial fiber which comprises forming e composite of filament-donning material and another material, both said materials being and being immiscible with each other so that each retains its separate identity, continuously feeding said composite through a plurality of adjacent orifices adapted to extrude the plurality of filaments which together constitute a sliver, soid materials being so disposed, substantially uniformly throughout the composite, as to present bodies of each material to the individual orifices at frequent intervals, the bodies of said other material filling the orifice cross section to the temporary exclusion of the filament-forming material, whereby to produce a silver from the several orifices comprising pieces of filamentiorming material overlapped and staggered longitudinally of the sliver, and after passage through the orifices separating said other material from the filament-forming material.

2. Method of forming a sliver of artificial fiber .which comprises forming a composite of filoment=forming materiel and another material, both said materials being in a fiowable condition and being immiscible with each other so that such retains its separate identity, continuously feeding said composite through a plurality of oldjacent orifices adapted to extrude the plurality of filaments which together constitute a sliver, ecid materials being so disposed, substantially uniformly throughout the composite, as to present bodies of each material to the individual orifices at frequent intervals, the bodies of said filling the orifice cross section to the temporary exclusion of the filament-forming material, whereby to produce a sliver from the several orifices comprising pieces of filamentiorming material overlapped and staggered longitudinslly of the sliver, and after passage through the orifices separating said other material from the filament-forming material while confining the sliver laterally.

3 Method of forming a sliver of artificial fiber which comprises forming a composite of filamentformlng material and another material, both said materials being in a fiowable condition and being immiscible with each other so that each retains its separate identity, continuously feeding said composite through a. plurality of adjacent orifices adapted to extrude the plurality of filaments which together constiimte a sliver, said materials in a floweble condition ill 3 being so disposed, substantially uniformly throughout the composite, as to present bodies or each material to the individual orifices at frequent intervals, the bodies of said other material filling the orifice cross section to the temporary exclusion of the filament-forming material, whereby to produce a silver from the several oriflees comprising pieces of filament-forming mate riol overlapped and staggered longitudinally of the sliver, and after passage throughthe orifices separating said other material from the filamentforming material and applying a twist to the sliver. s

4. Method of forming a sliver of artificial fiber which comprises forming a composite of a plurality of filament-forming materials and another material, all of said materials being in a fiowable condition and the said other materiel being 1mmiscible with the filament-forming materials so that said other. material retains its separate identity, continuously feeding said composite through a plurality of adjacent orifices adapted to extrude the plurality of filaments which together constitute a sliver, said materials being so disposed, substantially uniformly throughout the composite, as to present bodies of the filament-forming materials and bodies of said other material to the individual orifices at frequent intervals, the bodies of said other material filling the orifice cross section to the temporary exclusion of the moment-forming material, whereby to produce a silver from the several orifices comprising pieces of filament-forming material overlapped and staggered longitudinally or the sliver, and after passage through the orifices separating said other materiel from the filament-forming materiel.

5. Method of forming a sliver of artificial fiber which comprises forming a. composite of a plurality oi filsmentdorming materials in dispersed phase and another material in continuous phase, all of said materials being in a fiowable condition and the said other material being immiscible with the filement-forming materials so that said other material retains its separate identity, continuously feeding said composite through a plurality of adjacent orifices adapted to extrude the plurality of filaments which together constitute a sliver, said materials being so disposed, substantially uniformly throughout the composite, as

to present bodies of the filament-forming materials and bodies of said other individual orifices at frequent intervals, the bodies of said other material filling the orifice cross section to the temporary exclusion of the filament-forming material, whereby to produce a sliver from the several orifices comprising pieces of filament-forming material overlapped and staggered longitudinally of the sliver, and after passage through the orifices separating said other material from the filament forming material.

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